The lucky residents of the international Space Station pull 12-hour shifts, including two and a half hours of gym time and six and a half hours of lab work, among other duties. They sleep eight hours, leaving another four for goofing off in zero gravity. If the timing’s right, they call home to catch up. They watch their alma maters play football (the Army-Navy game is particularly popular). NASA has sent up playthings like guitars, keyboards, and a saxophone, as well as a chess set outfitted with Velcro to keep the pieces from floating away.